The aim of the proposed study is to determine the baroreceptor control of the cardiovascular system, cardiac and non-cardiac autonomic function, the response to anesthetic management and the properties of blood vessels from functionally different sites, in dogs chronially instrumented for the measurement of systemic and pulmonary hemodynamics, during the induction and resolution of an experimental renal hypertension. The hypertension will be induced by the controlled unilateral reduction of renal blood flow. Resolution of the latter will be achieved by the subsequent removal of the ischemic kidney. Baroreceptor function will be studied by the hemodynamic response to carotid hypotension and intravenous pressor injection; autonomic function by the progressive blockade of the vagi, Beta and Alpha adrengeric receptor sites; anesthesia by the response to induction, endotracheal intubation and step changes in the inspired concentrations of inhalational agents; blood vessel properties by sampling from systemic, pulmonary and baroreceptor bearing sites with subsequent analysis of water and electrolyte content, collagen and elastin content, active and passive mechanical properties. During a terminal procedure the baroreceptor control of pulsatile regional hemodynamics wll be studied using the isolated carotid sinus preparation with additional hemodynamic measurements in the renal, mesenteric, celiac and iliac, vascular beds. acute effects of an increased blood pressure upon the baroreceptor control of the distribution of cardiac output will be assessed in separate studies using the above preparation in acute dogs; the short term pressure rise being induced by inflation preparation in acute dogs; the short term pressure rise being induced by inflation of a hydraulic cuff around a single renal artery. The results of this study will improve understanding of the morphological and functional consequences of hypertension, particularly with respect to the sympathetic control of the regional delivery of blood flow in the awake and anesthetized animal.